Supercritical Hydrothermal Synthesis of Organic-Modified Ce1-xZrxO2-δ (0≤x≤1) Nanoparticles as a Low-Temperature Oxygen Carrier

In this study, organic surface-modified Ce1-xZrxO2-delta nanoparticles were synthesized using supercritical hydrothermal method. X-ray diffraction and energy-dispersive X-ray spectroscopy analysis results indicated Zr intake into the CeO2 lattice and vice versa. Results obtained from thermogravimetric analysis proved surface modification of Ce1-xZrxO2-delta nanoparticles with carboxylic acids. Decreased particle size caused by surface modification along with induction of Zr into the CeO2 lattice was found. Extraordinarily high oxygen storage capacity was obtained at low temperatures with a 70%-Zr loading sample, which showed 337.0 mu mol-O/g at 200 degrees C and 530.1 mu mol-O/g at 250 degrees C. High oxygen mobility in the oxide originated from the small particle size and size control effects by surface modification, together with the great amount of defect sites enabled by Zr substitution. Taken together, these results suggest that this is a promising material for use as an oxygen carrier to support low-temperature chemical looping process. Material performance as an oxygen carrier can be extracted by nano-size and surface-controlled effects, even exploring ordinary material composition, as ceria-zirconia.

Automated summary

In this study, organic surface-modified Ce1-xZrxO2-delta nanoparticles were synthesized using supercritical hydrothermal method. Zr intake into the CeO2 lattice and vice versa was observed. The surface modification of Ce1-xZrxO2-delta nanoparticles with carboxylic acids resulted in decreased particle size and induced Zr into the CeO2 lattice. The 70% Zr loading sample exhibited extraordinarily high oxygen storage capacity at low temperatures.